I got into a fellow's 182 to fly a flight check with him. A very well equipped, partly glass cockpit aircraft, with an additional: kneeboard on the pilot with an Ipad strapped to it, an Ipad on the control wheel, and an Ipad on a bendy stand fitted to a box in between the seats, which held heavens know what else. This pilot was not IFR qualified.
I pointed out that as the checking pilot, I could not reach the engine controls at all (third Ipad), and his reach was interfered. I insisted that Ipad three be removed before we flew, and unclipped fairly easily. He was over equipped.
In contrast, I once had to deliver a open cockpit aircraft a few hundred miles. I carried three photocopies of the relevant chart area (so I could have two blow away), and a wrist watch. I did just fine....